Milky Way: Thousands of black holes discovered in our galaxy

They are the remnants of old stars: thousands of small black holes in the Milky Way, the galaxy in which we live. What astronomers have long suspected has now been proven.

Milky Way: Thousands of black holes discovered in our galaxy

No, all se black holes will not suck our earth. They are too small and too far away. But what astronomers have discovered now near center of our home galaxy is still amazing. To understand this, however, we must first of all penetrate into even deeper depths of our universe.

A black hole – that is roughly speaking a place in space where gravitation is so immense that nothing more comes out of it. Not even light. That's why it's black. and invisible. So far, so obvious. As we know today, a gigantic black hole sits in center of every galaxy. Also in our home galaxy, Milky Way. And it's super mass rich, as astronomers say. Our black hole has a mass of 4.3 million times size of our sun! No wonder, n, that his powers are so powerful. Only how it was created remains as good as unexplained.

Telltale radiation

Better understood, however, are small black holes that stay behind when a star ends. They are also invisible, but can be seen indirectly, as long as y absorb matter from universe. For example, from a neighboring star of a double system. Because matter y attract is incredibly heated and emits radio waves, such black holes can be detected indirectly using X-ray telescopes.

Exactly in this way, a team around Charles Hailey from Columbia University in New York has now proven twelve small stellar black holes – within a radius of just 3.26 light years around center of galaxy, i.e. in immediate vicinity of Super mass-rich black hole in our galaxy. The researchers identified radiation outbreaks of twelve black holes that form double systems with normal stars. In same region, a furr 300 to 500 such double stars and 10,000 isolated black holes would have to be found, scientists write in magazine Nature (Hailey et al., 2018).

The researchers have calculated this from archived data collected by Chandra X-ray Observatory in space. This satellite, named almost 14 meters long after astronomer Subrahmanyan Chandrasekhar, was shot on its orbit in 1999 by Columbia Space Shuttle and registers almost 140,000 kilometers above earth X-rays, which are from particularly hot regions in Space: From stellar explosions, for example, or from regions with black holes.

Because it is known that many new stars are forming in vicinity of supermassive black holes – and n many die again – found scientists are not particularly surprised at this moment. Neverless, it is a success that twelve of se star corpses, as one might call stellar black holes casually, are now indirectly proven. They are remnants of large stars that have collapsed after consumption of ir nuclear fuel supply.

"The ory predicts up to 20,000 such stellar black holes in central Parsec of Milky Way," explains Charles Hailey of Columbia University in United States and his colleagues. As Parsec, astronomers refer to a distance of 3.26 light years. "But so far, no overabundance of black holes has been detected in this region."

Because most stellar black holes are quiet, so do not emit any conspicuous radiation. Only black holes that matter from a second star fall into are betrayed by sporadic bursts of X-rays. But well-proven, energy-rich X-rays are rare – only every few hundred years one would be expected from Milky Way Center. Hailey and his colleagues have refore searched for traces of black holes in double systems in ir quiet phase in archival data of X-Ray satellite Chandra – because even n y repel X-rays from and on, albeit weaker.

"This is how our results confirm oretical predictions," says Hailey. "The Milky Way is only galaxy where we can see how small black holes interact with big, central black hole. For example, we get information about kind of gravitational waves generated by se black holes. " The Galactic Center thus become a kind of laboratory for researchers to investigate black holes.

Date Of Update: 05 April 2018, 12:02
NEXT NEWS